code: def test_gaussian():
      data = np.zeros((128, 128)) + 0.5
      data_gaussian = random_noise(data, rng=42, var=0.01)
      assert 0.008 < data_gaussian.var() < 0.012
  
      data_gaussian = random_noise(data, rng=42, mean=0.3, var=0.015)
      assert 0.28 < data_gaussian.mean() - 0.5 < 0.32
      assert 0.012 < data_gaussian.var() < 0.018
  
file_path: scikit-image/skimage/util/tests/test_random_noise.py
imports: from skimage._shared import testing
  from skimage._shared.testing import assert_array_equal, assert_allclose
  import numpy
  from skimage.data import camera
  from skimage.util import random_noise, img_as_float
label_desc: Use image node_id 7 for calling a global function with example usage: test_gaussian() without return types